Buggy code:
public class MachineModel { protected Node xml = null ; @ SuppressWarnings ( "unused" ) private Point5d minimum ; private Point5d maximum ; private EnumMap < AxisId , Endstops > endstops = new EnumMap < AxisId , Endstops > ( AxisId . class ) ; private Set < AxisId > axes = EnumSet . noneOf ( AxisId . class ) ; private Point5d maximumFeedrates ; private Point5d homingFeedrates ; private Point5d stepsPerMM ; private Point5d timeOut ; protected boolean drivesEnabled = true ; protected int gearRatio = 0 ; protected Vector < ToolModel > tools ; protected final AtomicReference < ToolModel > currentTool = new AtomicReference < ToolModel > ( ) ; protected final ToolModel nullTool = new ToolModel ( ) ; protected Vector < ClampModel > clamps ; protected Vector < WipeModel > wipes = new Vector < WipeModel > ( ) ; protected File dualstartBookendCode = null ; protected File startBookendCode = null ; protected File endBookendCode = null ; protected BuildVolume buildVolume ; private MachineType machineType = null ; public MachineModel ( ) { } public void loadXML ( Node node ) { } private void parseType ( ) { } private void parseExclusion ( ) { } private void parseWipes ( ) { } private void parseAxes ( ) { } private void parseClamps ( ) { } private void parseTools ( ) { } private void parseBuildVolume ( ) { } private void parseGCode ( ) { if ( XML . hasChildNode ( xml , "bookend" ) ) { Node bookend = XML . getChildNodeByName ( xml , "bookend" ) ; String dualstartLocation = XML . getAttributeValue ( bookend , "dualstart" ) ; String startLocation = XML . getAttributeValue ( bookend , "start" ) ; String endLocation = XML . getAttributeValue ( bookend , "end" ) ; if ( dualstartLocation != null ) <START_BUG> dualstartBookendCode = new File ( startLocation ) ; <END_BUG> if ( startLocation != null ) startBookendCode = new File ( startLocation ) ; if ( endLocation != null ) endBookendCode = new File ( endLocation ) ; } else { logger . severe ( "No<seq2seq4repair_space>bookend<seq2seq4repair_space>metadata<seq2seq4repair_space>specified<seq2seq4repair_space>for<seq2seq4repair_space>this<seq2seq4repair_space>machine" ) ; } } public Set < AxisId > getAvailableAxes ( ) { } public boolean hasAxis ( AxisId id ) { } public Point5d stepsToMM ( Point5d steps ) { } public Point5d getStepsPerMM ( ) { } public Point5d mmToSteps ( Point5d mm ) { } public Point5d mmToSteps ( Point5d mm , Point5d excess ) { } public void enableDrives ( ) { } public void disableDrives ( ) { } public boolean areDrivesEnabled ( ) { } public void changeGearRatio ( int ratioIndex ) { } public ClampModel getClamp ( int index ) { } public void selectTool ( int index ) { } public ToolModel currentTool ( ) { } public ToolModel getTool ( int index ) { } public BuildVolume getBuildVolume ( ) { } public Vector < ToolModel > getTools ( ) { } public void addTool ( ToolModel t ) { } public void setTool ( int index , ToolModel t ) { } public Point5d getMaximumFeedrates ( ) { } public Point5d getHomingFeedrates ( ) { } public Point5d getTimeOut ( ) { } public Endstops getEndstops ( AxisId axis ) { } public Vector < WipeModel > getWipes ( ) { } public WipeModel getWipeFor ( ToolheadAlias tool ) { } public File getDualstartBookendCode ( ) { } public File getStartBookendCode ( ) { } public File getEndBookendCode ( ) { } public MachineType getMachineType ( ) { } }

Fix:
dualstartBookendCode = new File ( dualstartLocation ) ;